(a) Field of the Invention
This invention relates to stamping apparatus for providing workpieces, such as metallurgical or rolled products, with different embossed marks, which apparatus comprises a plurality of juxtaposed punches which are axially slidably mounted in a punch holder, and a punch actuator for selectively actuating at least one of said punches.
(b) Prior Art
In known apparatus of that kind, each punch carries a pattern corresponding to one of the embossed marks which are to be formed. To provide a workpiece with one of said embossed marks, the associated punch is moved by means of the punch holder into registry with the punch actuator, which usually consists of a fluid-operable cylinder. The punch holder usually consists of a carriage, which is movable transversely to the punch actuator, or of a wheel, which carries the punches arranged in a circular series, so that the wheel can be rotated to move the required punch to its stamping position. These known designs have the disadvantage that, for the provision of a given mark, the punch holder must be moved to a position in which the punch provided with the required pattern registers with the punch actuator. This requires a separate control movement so that the stamping rate is highly restricted. Besides, the required control movement involves expensive control structures. Only a small number of different embossed marks can be provided by means of that apparatus so that a larger number of stamping operations are required for a sufficiently large information.